Laser control method, laser apparatus, laser treatment method used for the same, laser treatment apparatus

Abstract

A laser controlling method can generate laser of stable laser pulses, and eliminate useless time from a machining procedure. The method uses a gain medium and a Q-switch, and emits exciting light to the gain medium, thereby setting the Q-switch in a continuous oscillation mode, and prepares a given Q-switch pause time before a laser pulse is generated. When the continuous oscillation is kept going longer than a given time, the control method sets a Q-switch pause time for obtaining a first laser pulse to be different from a Q-switch pause time for obtaining a second laser pulse and onward.

1. A method for controlling a laser, comprising:
 setting an OFF time value, 
 initializing a counter to cause a laser to emit N laser pulses, 
 continuously irradiating a gain medium with light, thereby turning a Q-switch ON for a first ON time period, 
 then turning the Q-switch OFF for a first OFF time period to increase a gain of the laser when the first ON time period is longer in duration than said OFF time value, 
 turning the Q-switch ON; 
 turning the Q-switch OFF for a second OFF time period to increase a gain of the laser when the first ON time period is shorter in duration than said OFF time value, the first OFF time period being of different duration from the second OFF time period, 
 turning the Q-switch ON to cause said laser to emit a first of said N laser pulses, and 
 turning the Q-switch OFF and ON for N−1 successive cycles to emit N−1 laser pulses, wherein the Q-switch is turned OFF for a second OFF time period to obtain each of the N−1 laser pulses, and the second OFF time period is equal to said OFF time value. 
 
     
     
       2. The method of  claim 1 , wherein said first OFF time period is shorter than said second OFF time period when the gain medium has a short fluorescent life. 
     
     
       3. The method of  claim 1 , the laser comprising a nonlinear crystal disposed with an extra-cavity device for obtaining a harmonic laser. 
     
     
       4. The method of  claim 1 , the laser comprising a nonlinear crystal disposed with an intra-cavity device for obtaining a harmonic laser.